using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using Developpez.Dotnet.Windows.Collections;
using NUnit.Framework;

namespace Developpez.Dotnet.Windows.Tests.Collections
{
    [TestFixture]
    public class RangeObservableCollectionTests
    {
        [Test]
        public void Test_AddRange()
        {
            var collection = new RangeObservableCollection<int>();

            string expectedEvents = "+1+3+2+1";
            var expectedCollection = new List<int>();

            StringBuilder sbEvents = new StringBuilder();

            collection.CollectionChanged += (sender, e) =>
            {
                Assert.AreEqual(NotifyCollectionChangedAction.Add, e.Action);
                sbEvents.AppendFormat("+{0}", e.NewItems.Count);
            };

            collection.Add(1);
            expectedCollection.Add(1);
            collection.AddRange(new[] { 2, 3, 4 });
            expectedCollection.AddRange(new[] { 2, 3, 4 });
            collection.AddRange(new[] { 5, 6 });
            expectedCollection.AddRange(new[] { 5, 6 });
            collection.Add(7);
            expectedCollection.Add(7);

            string actualEvents = sbEvents.ToString();
            Assert.AreEqual(expectedEvents, actualEvents);
            Assert.IsTrue(expectedCollection.SequenceEqual(collection));
        }

        [Test]
        public void Test_InsertRange()
        {
            var collection = new RangeObservableCollection<int>();

            string expectedEvents = "+1+3+2+1";
            var expectedCollection = new List<int>();

            StringBuilder sbEvents = new StringBuilder();

            collection.CollectionChanged += (sender, e) =>
            {
                Assert.AreEqual(NotifyCollectionChangedAction.Add, e.Action);
                sbEvents.AppendFormat("+{0}", e.NewItems.Count);
            };

            collection.Insert(0, 1);
            expectedCollection.Insert(0, 1);
            collection.InsertRange(0, new[] { 2, 3, 4 });
            expectedCollection.InsertRange(0, new[] { 2, 3, 4 });
            collection.InsertRange(2, new[] { 5, 6 });
            expectedCollection.InsertRange(2, new[] { 5, 6 });
            collection.Insert(3, 7);
            expectedCollection.Insert(3, 7);

            string actualEvents = sbEvents.ToString();
            Assert.AreEqual(expectedEvents, actualEvents);
            Assert.IsTrue(expectedCollection.SequenceEqual(collection));
        }

        [Test]
        public void Test_RemoveRange()
        {
            var collection = new RangeObservableCollection<int>(Enumerable.Range(0, 10));

            string expectedEvents = "-1-3-2-1";
            var expectedCollection = Enumerable.Range(0, 10).ToList();

            StringBuilder sbEvents = new StringBuilder();

            collection.CollectionChanged += (sender, e) =>
            {
                Assert.AreEqual(NotifyCollectionChangedAction.Remove, e.Action);
                sbEvents.AppendFormat("-{0}", e.OldItems.Count);
            };

            collection.RemoveAt(0);
            expectedCollection.RemoveAt(0);
            collection.RemoveRange(0, 3);
            expectedCollection.RemoveRange(0, 3);
            collection.RemoveRange(2, 2);
            expectedCollection.RemoveRange(2, 2);
            collection.RemoveAt(3);
            expectedCollection.RemoveAt(3);

            string actualEvents = sbEvents.ToString();
            Assert.AreEqual(expectedEvents, actualEvents);
            Assert.IsTrue(expectedCollection.SequenceEqual(collection));
        }

        [Test]
        public void Test_RemoveAll()
        {
            var collection = new RangeObservableCollection<int>(Enumerable.Range(0, 10));

            string expectedEvents = "-3-3-1";
            var expectedCollection = Enumerable.Range(0, 10).ToList();

            StringBuilder sbEvents = new StringBuilder();

            collection.CollectionChanged += (sender, e) =>
            {
                Assert.AreEqual(NotifyCollectionChangedAction.Remove, e.Action);
                sbEvents.AppendFormat("-{0}", e.OldItems.Count);
            };

            Predicate<int> notDivisibleBy4 = (i) => i % 4 != 0;

            collection.RemoveAll(notDivisibleBy4);
            expectedCollection.RemoveAll(notDivisibleBy4);

            string actualEvents = sbEvents.ToString();
            Assert.AreEqual(expectedEvents, actualEvents);
            Assert.IsTrue(expectedCollection.SequenceEqual(collection));

        }

        [Test]
        public void Test_ReplaceRange()
        {
            var collection = new RangeObservableCollection<int>(Enumerable.Range(0, 10));
            string expectedEvents = "-3-2";
            var expectedCollection = new[] { 0, 1, 4, 3, 2, 6, 5, 7, 8, 9};

            StringBuilder sbEvents = new StringBuilder();

            collection.CollectionChanged += (sender, e) =>
            {
                Assert.AreEqual(NotifyCollectionChangedAction.Replace, e.Action);
                Assert.AreEqual(e.OldItems.Count, e.NewItems.Count);
                sbEvents.AppendFormat("-{0}", e.OldItems.Count);
            };

            collection.ReplaceRange(2, new[] { 4, 3, 2 });
            collection.ReplaceRange(5, new[] { 6, 5 });

            string actualEvents = sbEvents.ToString();
            Assert.AreEqual(expectedEvents, actualEvents);
            Assert.IsTrue(expectedCollection.SequenceEqual(collection));
        }
    }
}